Effect of four mid-altitude maize varieties on oviposition, development and sex ratio of Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae)

Insects are the principal pests of maize in storage. The maize weevil, Sitophilus zeamais (Motschulsky), is of prime concern to farmers in the western highlands of Cameroon. Chemical insecticides for its control are costly and not readily available in Cameroon, hence the need for other non-chemical alternatives. Laboratory studies were carried out on the developmental biology of S. zeamais on four commonly cultivated mid-altitude maize varieties : KASAI, ATP, COCA-SR and ACR98TZEMSR-W. These varieties significantly influenced S. zeamais oviposition, development and emerged F1 progeny and grain weight loss. Duration of weevil development was significantly longer on COCA-SR and ATP than on the two other maize varieties. A significantly lower number of F1 progeny emerged from COCA-SR and ATP. Mean grain weight loss was lowest in COCA-SR and was correlated with duration of development. The reproductive potential of S. zeamais was significantly different on the four maize varieties, COCA-SR being the least favourable host.